Project summary: This project performs an innovative, integrated analysis of clinical, health policy, and health economic questions relevant to curative treatments for sickle cell disease (SCD) using cost-effectiveness analysis of a prospective patient cohort. The project is timely and of great significance to individuals, providers, and health systems as the rapid advances in the field of allogeneic hematopoietic cell transplantation (alloHCT) for SCD now warrant further investigation of this treatment option in the context of a varied landscape of therapeutic options for SCD. Specifically, critical improvements in supportive care have improved the safety and efficacy of alloHCT for SCD from a matched sibling donor (MSD) resulting in a dramatic increase in the acceptability of such transplants. This has resulted in the emergence of efforts to expand the availability of alloHCT to individuals without a MSD using alternate donors. At the same time, health policy is changing the landscape for alloHCT and curative therapies for SCD. In 2016, CMS included alloHCT for SCD in the national coverage determination with continued evidence development including focus on case control studies and quality of life assessment. Therefore, we have a clear mandate to understand the implications of alloHCT on health, quality of life, finances and service utilization in the short and long term compared to established conventional therapies. This K23 proposal plans to address this gap in understanding with a comprehensive cost-effectiveness analysis (CEA) according to the following steps: 1) define transition probabilities from published literature to serve as benchmarks or reference cases for our prospective analysis 2) use a novel methodology to translate prospectively collected PROMIS measures surveyed in the STELLaR study into preference based utility scores necessary for CEA 3) obtain prospective adjusted costs for STELLaR cases and controls 4) create and analyze a Markov model that incorporates all data from Steps 1-3 to determine the incremental cost-effectiveness ratio for each treatment strategy. We will also determine financial hardship and service utilization from a patient perspective in order to understand the depth of impact of these therapies on patients and families. The results of this K23 study will provide context for the affects of each treatment on patients' health, quality of life, finances, and the health system in a way that will aid individual decision-making by predicting the optimal treatment strategy. These findings will ultimately serve as the basis for tools to stratify disease severity and prognostic risk as well as create a scientific methodology to study other pediatric diseases.